It is a well-known fact that in the United States Navy as well as in the Royal Navy and French Navy all combatant submarines are nuclear-powered. At the same time as Russia, China and India operate not only nuclear-powered submarines, but also diesel-electric submarines.
There are some sophisticated models among modern diesel-electric submarines. I reckon the most advanced subs of that type are Sōryū-class attack submarines (Japan) and Type 214 class submarines (Germany). Sōryū-class submarines are fitted with air-independent propulsion based on Kockums stirling engines license-built by Kawasaki Heavy Industries, allowing them to stay submerged for longer periods of time. Therefore, I am not surprised that Australian officials are leaning towards replacing the Collins-class submarine with Sōryū-class boats bought from Japan.
Apparently, France is going to return to the club of diesel-electric submarines. As naval-technology.com reported, SMX-Océan, a conventionally powered attack submarine design concept, unveiled by DCNS Group, is based on the basic Barracuda-class nuclear submarine layout including weapons, masts and combat system. The SMX-Océan submarine will be a transposition of the Barracuda SSN nuclear powered attack submarine into diesel-electric submarine (SSK). It is expected to enter into French Navy’s service by 2017.
The new multi-role submarine will be suitable for deployment in anti-surface warfare (ASuW), anti-submarine warfare (ASW), anti-air warfare (AAW), land attack and even Special Forces missions. Special operations forces (SOF) equipment for 16 divers will be fitted to the sub, as will an internal reserved area, lock out chamber for eight divers, and an external watertight storage. It will also feature a dry dock shelter, hyperbaric chamber, swimmers delivery vehicle, and unmanned underwater vehicle (UUV) dock. The SMX-Océan submarine will integrate sensors with manned or unmanned vehicles that provide capability to gather intelligence in four domains including air, surface, under the sea and on the land. It will be capable of launching UUVs and unmanned air vehicles (UAVs).
With up to three months’ endurance, an SMX-Océan could cross the Atlantic six times without surfacing. DCNS teams have developed and combined a number of innovations including a high-performance air-independent propulsion (AIP) system using second-generation fuel cells for submerged endurance of up to three weeks (21 days). With a total of 34 weapons including torpedoes, mines, anti-ship missiles, cruise missiles and anti-air missiles, the SMX-Océan’s firepower will be unprecedented for an SSK. The SMX-Océan concept design also includes vertical launchers to provide a salvo capability for cruise missile strikes on land targets.
Length: 100 m (330ft)
Height: 15.5 m
Beam: 8.8 m (28.9ft)
Surface displacement: 4,750 t
Maximum diving depth: 350 m
Maximum speed, submerged: 20 kts
Range: 18,000 nmi at 10 kts speed